Heater construction



Nov. 21, 1933.- v w, M. Ross v 1,935,617

HEATER CONSTRUCTION Original Filed Feb. 16. 1925 2 Sheets-Sheet 1 Z ze INVENTUR.

Nov.2'1,-1933. -VWMCRQSS'- 1,935,617?

HEATER CONSTRUCTION Original Filed Feb. 16. 1925 2 Sheets-Sheet 2 Vapor/zw.; /9 7,

I A i 4 A- gli 27 i E K l g INVENTOR.

M-y/a///vss:

r @ffl/ess.; By l j /x f l M @Mm Patented Nov, 2l, i3d

, MATER CGNSTRUC'MN Walter lvl. Cross, Kansas City, Mo., assigner te Babcock d: Wilcox filo.,

New Yarn, N. Y., a corporation ci New Jersey amusants February is, i925, serai No. aan Renewed .ianuary 29, 11.932

(Claims.

This invention has reference to fluid heaters of the drumless type, in which the fluid enters as a liquid at one end of a long conduit and emerges` as vapor.

One of the salient features of the invention is the provision of a generator of the aforesaid character which is differentiated from the socalled ilash or semi-dash boiler in that the iluid extends as a liquid through the larger portion of the entire conduit, or conduits in parallel, and receives pre-heating in thecooler gas zone, then enters a vaporizing section in the hottest gas zone, from which it enters a superheating section at a gas zone of intermediate temperature with the conduits thereof protected by the location of the vaporizing section.

A further feature is an arrangement such i that the iiuid medium may be utilized in successive stages of expansion to saturation and returned to the superheating section in the locanl tion above described for the superheater for the addition of heat.

An additional object resides in the arrangement of the sections of the conduits in such form that there is freedom for expansiomand provision for cleaning the interior of the conduit sections.

ln the drawings- Fig. 1 is a plan View of a generator constructed in accordance with the present invention, but with the insulated top and horizontal baille removed to disclose the tube arrangements;

Fig. 2 is a transverse, vertical sectional view taken through the central portion of the heater shown in Fig. 1.

Fig. 3 is a diagrammatic view showing the continuity of the path` of the I'luid from liquid entrance to final outlet;

Fig. 4 is a fragmentary front elevation, in section of the header, of one side of the tube banks; and

other than that herein described, but in theV Fig. 5 is a fragmentary sectional view along the present instance it is shown, for the purposes of illustration only, as an internally fired tunnel for use with gas or oil, heat being radiated from all sides thereof excepting the bottom.

Ports or openings are provided at the top of this tunnel-shaped heater member through which the gases have their exit. Air may be supplied to the burner along with the gas if desired, or a separate fuel supply may be used,

but, if desirable, dependent upon conditions, the @5 supply of air, the supply of combustible and air, or the supply of combustible alone may be fun1 nished through a pipe 3 incorporating a pre= heater 4 located in path of the exit gases from the furnace, and which pipe is continued to the heating means 2.

The preheater e, in the form shown, consists of a group of tubes extending between two anges, but such form oi preheater is shown merely for the purpose of illustration of a type 35 which may be used.

The chamber l, which is closed at the top except for the outlet 5 to the ue, and in which the preheater t is disposed, comprises a horizontal" baie 1l near the top and through which are 8@ peripheral ports 12,'as indicated in Fig. 2. Beneath this baiiie and above the source of heat 2, are groups of curved tubes forming a conduit, and which is divided into three sections, namely, an outer preheating .section constituting yve lateral rows, an inner vaporizing section at the lcenter constituted of two rows, and an intermediate superheating section, as shown.

lt is to be noted that the connections between the ends of adjacent lines are practically in the form of return bends as indicated in Figs. l and 5, but with the headers provided with plugs 28 opposite the end of each section which may be removed for the purpose of cleaning the tubes. The connections between the ends of adjacent tubes are made at one side oi the chamber and the, tube ends at the opposite side, designated diagrammatically in Fig. l. as 25, are merely freturn bends which cause the liquid to loop back through the next successive tube through which the liquid is passing, the tube ends being connected up in such a manner that a continuous passage is effected from the inlet to the outlet of the boiler.

It will be noted that there is provided what might be termed a once through" boiler which has a multiplicity of parallel sections serially connected and of U-shape form so that expansion and contraction are readily taken care of, the

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5 towards the center of the furnace where it is vaporized at the hottest gas zone, from which it inallygoes to the zone between the preheating and vaporizing sections where it receives superheat in the superheater which is protected by the vaporizing tubes, as shown.

In connection with Fig. 3 there is shown the water entering at 13, passing through the serially arranged preheating conduits 6 through which the uid advances from the outer or cooler portions of the heating chamber inwardly towards the hotter portion thereof, and then .through pipe 14 to the vaporizing tubes '7, from which it travels through pipe 15 to the rst stage of superheating 8. From this it leaves through the pipe 16 to the expansion stage 1'7, from which it is returned through 'the pipe 18 to a second stage superheater 9, leaving this superheater through the connection 19 to a second expansion stage 20, from which it returns through the pipe 21 and is received and passed through the third stage superheater 10, from which it emerges through the pipe 22 to a third expansion stage 23, the condensate being recovered by thecondenser 24.

In practicing the invention it is understood that the generator is preferably operated at approximately 1,500 pounds pressure, and the uid maintained liquid throughout the major portion oi.' the continuous conduit represented by the sectional views described, and hence no appreciable amount of evaporation occurs until the vaporizing tubes have been reached by the liquid, but that the liquid is completely converted into vapor before it reaches the superheating surface hereinbefore described.

As described in connection with Fig. 3, the original 1,500 pounds pressure may be reduced through an expansion stage, such as a turbine or the like, to 1,000 pounds, such expansion stage being diagrammatically indicated in Fig. 3 at 17, and from which it is then returned to the second stage superheater 9 which, in practice, may be positioned adjacent the superheater 8, and from which it is then led to the expansion stage 20 and back to a third stage superheater indicated at 10 and similarly positioned with respect to the general assembly.

The nal stage of expansion 23 may exhaust to a condenser 24, or the like. l

It is to be noted that plugs 28 closing openings 27, functioning as return bends for the tubes, also provide access by means of which a ilexible cleaning element may be used to relieve the tubes of any scale or other material.

While in the ioregoinglthere has been described preferred forms which the invention assumes in practice, it is nevertheless to be understood that other modifications may be provided dependent upon conditions under which the invention is to be used, and a number of conduits may be arranged in parallel with each having a serial iiow path.

I claim:

1. A heater of the character described, consisting of an insulated combustion chamber, a source oi' heat therein, a plurality of banks of U-tubes positioned about the heating means in semi-circle arrangement and connected to produce a continuous travel of the heating medium therethrough,

a ue in the upper portion of the combustion chamber, an upper horizontally positioned baie positioned to direct the combustion gases over the tubes in their travel to the flue.

2. A heater of the character described, consisting of an insulated combustion chamber, a source of -heat therein, a plurality of banks of U-tubes horizontally positioned about the heating means in a semi-circle arrangement and connected to produce a continuous travel of the medium therethrough, said tubes comprising a preheating.

stage, a vaporizing stage and a plurality of superheating stages, the outer tubes of the semi-circle comprising the preheating stage, the inner tubes the vaporizing stage and the intermediate tubes vertically separated into three stages of superheat, and a flue in the upper portion of the combustion chamber for carrying oil the spent gases.

3. A heater of the character described, comprising a combustion chamber having a source of heat in the lower central portion thereof, a plurality of banks of U-tubes positioned about the heating means in semi-circular arrangement, the said banks of tubes connected to produce a continuous flow of the circulating medium, the outer banks of tubes, or those furthest from the heat source, comprising a preheating stage, the inner banks of tubes a vaporizing stage and the intermediate banks stages oi superheat, and a iiue in the upper portion of the combustion chamber for discharging the spent combustion gases.

4. A heater of the character described, comprising a combustion chamber having a source of heat in the lower central portion thereof, a plurality of banks of U-tubes positioned about the heating means in semi-circular arrangement, the said banks of tubes connected to produce a continuous ow of the circulating medium, the outer banks of tubes, or those furthest from the heat source, comprising a preheating stage, the inner banks of tubes a vaporizing stage and the intermediate banks stages of superheat, a iiue in the upper portion of the combustion chamber for carrying oi the spent gases.

5. A heater ofthe character described comprising a combustion chamber, a source of heat therein, a plurality of banks of U-tubes positioned about said source of heat in a semi-circular arrangement, said source of heat being intermediate the ends of the tubes and arranged to supply heat by radiant energy and by convection over the tube surfaces, the said banks of tubes connected to produce a continuous iiow of the circulating medium, said banks being connected in vertical rows to pass the circulating medium through the bank of tubes farthest from the heat source, thence through the bank of tubes closest to the heat source and nally through the bank of tubes intermediate the two last mentioned banks, and a flue in the upper portion of the chamber for discharging the spent gases.

6. A heater including a casing and a centrally disposed iire, bent tubes arranged with the path of the heating gases from the center crossing the tubes toward the casing and out, said tubes serially connected and arranged in groups with reference to the flow of heated gases, a feed pump water supply delivering water to that one of said groups of tubes which is located in the coolest gas zone and through which it hows, rto the second of said groups located in the hottest zone supplying said second group with heated water, and a connection from said second groupto a third group located in the zone of intermediate gas temperature whereby the steam generated in, the second group becomes superheated in the third group, and an outlet from the last group to a point of use.

7. A heater including a casing and centrally disposed re, bent tubes arranged with thepath of the heating gases from the center crossing the tubes toward the casing and out, said tubes serially connected and arranged in groups with reference to the dow of heated gases, a feed pump vwater supply delivering water to that one of said groups of tubes which is located in the coolest gas zone and through which it ows to the second isA 

